15. Analytical Techniques:IR, NMR, Mass Spect

Draw the ¹H NMR spectrum you would expect to see for each of the molecules in Assessment 15.63.

(d)

Sketch the following spectra that would be obtained for 2-chloroethanol:

a. The ¹H NMR spectrum for an anhydrous sample of the alcohol.

In the lab, ¹H NMR is often used to verify that a reaction has worked as expected by comparing the product spectrum with what is expected. Given the ¹H NMR of the reactant shown, draw the spectrum you'd expect to see of the product that results.

<IMAGE>

Give the spectral assignments for the protons in isobutyl alcohol (Solved Problem 13-4). For example, H^a is a singlet, area = 1, at δ2.4.

Draw the ¹H NMR spectrum you would expect to see for each of the molecules in Assessment 15.63.

(c)

Draw a spectrum for each of the following molecules, being sure to indicate the multiplicity, integration, and chemical shift of each peak. Label each signal based on the set of equivalent hydrogens to which it corresponds.

(c)

The following proton NMR spectrum is of a compound of molecular formula C₃H₈O.

<IMAGE>

(a) Propose a structure for this compound.

(b) Assign peaks to show which protons give rise to which signals in the spectrum.

Draw the ¹H NMR spectrum you would expect to see for each of the molecules in Assessment 15.63.

(b)

Draw the expected NMR spectrum of methyl propionate, and point out how it differs from the spectrum of ethyl acetate.

Assign the peaks in the ¹H NMR spectrum for the molecule shown.

<IMAGE>

Sketch the following spectra that would be obtained for 2-chloroethanol:

b. The ¹H NMR spectrum for a sample of the alcohol that contains a trace amount of acid.

An unknown compound has the molecular formula C₉H₁₁Br. Its proton NMR spectrum shows the following absorptions:

singlet, δ7.1, integral 44 mm

singlet, δ2.3, integral 130 mm

singlet, δ2.2, integral 67 mm

Propose a structure for this compound.

Sketch your predictions of the proton NMR spectra of the following compounds.

(b)

The spectrum shown here is for a molecule with a molecular formula of C₄H₉Cl. Suggest a structure for this molecule.

<IMAGE>

(a) Using the ¹H NMR spectra, identify the reactants and product for this reaction.

<IMAGE>